Re: [Bugme-new] [Bug 11144] New: dhcp doesn't work with iwl4965

[David Miller <davem@davemloft.net>]

From: Patrick McHardy <kaber@trash.net>
Date: Wed, 23 Jul 2008 18:25:48 +0200

> We can't fit them into the cb together, I don't see a way to
> shrink ieee80211_tx_info.
> 
> Maybe one of the wireless folks can suggest something? Is it
> really necessary to pass the full struct ieee80211_tx_info
> through the qdisc layer, or could the struct be split? It
> needs to find a way to co-exist peacefully with qdiscs'
> skb->cb usage.

This is another area that got mangled up in the ->select_queue()
conversion of the WME bits, but in another aspect this problem
existed beforehand as well.

Specifically, when RX packets get requeued out to transmit in
the code in net/mac80211/rx.c that resends packets back out the
wireless device by setting a bit in the SKB CB then calling
dev_queue_xmit().

That's completely illegal :-)

There's a ton of stuff in that structure, I can't see how to
make it smaller either.  Maybe some bits only matter through
the layers of the TX mac80211 stack and thus can be passed
as parameters during such processing?